/*
 * Copyright 2013 Robert Peszek.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package fpig.lists.functions

import fpig.util.CallUtil
import fpig.util.FunUtil;
import fpig.lists.structures.FunList
import fpig.lists.structures.LazyList;
import fpig.lists.functions.impl.*

/**
 * List functions for generating infinite lists
 *
 * http://code.google.com/p/fpiglet/
 * @author Robert Peszek
 */
class Infinity {
	
	static Closure getStreamFrom() {
		 {n -> FunList.EMPTYLIST.build(n, { Infinity.streamFrom(n+1) }) }
    }
	
	static Closure naturalNumbers = { -> Infinity.streamFrom(1)}
	
	static Closure getRepeat() {
		{a -> FunList.EMPTYLIST.build(a, { Infinity.repeat(a) }) }
    }
	
	static Closure getIterateC() {
		{Closure f, a -> FunList.EMPTYLIST.build(a, { Infinity.iterate(f, f(a)) }) }
	} 
	
	static Closure iterate = CallUtil.toFunction Infinity.iterateC
}
